This invention relates generally to fluid delivery lines providing fluid communication between two fixed locations, the lines being composed of tubing and having one or more bends. More particularly, the present invention relates to the injection line providing fluid communication between an injection pump and an injector of a vehicle having a fuel injection system.
The fuel injection pump and fuel injector or a vehicle fuel injection system are generally both rigidly mounted in place. The injection line providing fluid communication therebetween has been found to be subject to premature failure due to the cyclical stresses imposed thereon by the hydraulic pressure pulses imposed on the injection line by the injection pump. Consequently, such injection lines have been either manufactured of materials having greater resistance to the cyclical stresses or are replaced on a periodic basis. The stress resistant materials are more expensive than the non-stress resistant materials and may be more difficult to manufacture. Periodic replacement of injection lines made from non-stress resistant material is time consuming and requires additional expense.
Briefly stated, the invention in a preferred form is a method for optimizing the geometry of a line providing fluid communication between an outlet of a pump and an inlet, the pump and inlet each having a fixed location, where the pump imposes a periodic pressure pulse on the tubing composing the line. Such line may be found between a fuel injection pump outlet and a fuel injection nozzle inlet. The method comprises the steps of identifying a basic design of the line using conventional industry practices for the specific application and making an initial determination as to the minimum number of bends which are required by the basic line design. If the tubing can be routed in a straight line from the pump outlet to the inlet with no bends required, a finite element analysis is performed to determine the minimum and maximum loading on the tubing imposed by the expected pressure pulse and the material of the tubing is selected to satisfy design safety factors with the minimal material cost. If the tubing must be bent, the bend routing is established to best fit the installation constraints set by the design layout, a determination is made whether the line may be routed in a single plane instead of in multiple planes, the centerline of the inlet is aligned with the centerline of the pump outlet if allowed by the location and orientation of the discharge end of the line for the proposed bend routing, the quantity of bends is verified to be minimized, the radii of the bends is maximized within installation constraints using one common radius, a finite element analysis is performed to determine the minimum and maximum loading on the tubing imposed by the expected pressure pulse and the material of the tubing is selected to satisfy design safety factors with the minimal material cost.
It is an object of the invention to provide a new and improved method for optimizing the geometry of a line providing fluid communication between an outlet of a pump and an inlet, the pump and inlet each having a fixed location.
It is also an object of the invention to provide a new and improved method for optimizing the geometry of a line providing fluid communication between a fuel injection pump outlet and a fuel injection nozzle inlet.
Other objects and advantages of the invention will become apparent from the drawings and specification.